The present invention relates to a storage technique, particularly to management and control of storage devices in a computer system and more specifically to an effective technique applied to a storage area network system including storage device-containing storage subsystems, fiber channel switches, and servers.
Increase in scale and capacity of data storage devices for various kinds of databases or WEB servers has been advanced with the development of information-oriented society such as popularization of the Internet. The concept “storage area network system” is known as a configuration used in place of a conventional configuration in which private storage subsystems are connected to one host so as to be subordinate to the host. In the storage area network system, a plurality of storage subsystems are connected to one another through a private information network to thereby logically construct one huge storage device in a state in which a plurality of hosts externally connected to the storage area network system need not be conscious of the storage subsystems individually.
In a system having such a storage area network environment constructed to have a large number of disk devices (logical units, logical volumes, and so on), a server needs to recognize necessary disk devices present in the storage area network environment when the server starts or when the server executes a disk device recognition process. The server, however, tries to recognize all accessible disk devices regardless of whether or not the server actually uses the disk devices.
In the system having a storage area network environment in which a large number of disk devices are present, when a server starts or when a server executes a disk device recognition process, a large amount of time may be required for the server's start or recognition of disk devices because the server also has to recognize disk devices not intended to be used by the server. Moreover, because the number of disk devices that can be recognized by the server is limited in accordance with the capacity and performance of the server or of an operating system of the server, the server may become inoperative when the number of the all disk devices exceeds the limit.